I believe this glitch occurs on fresh/re-installs? of the current stable version.
Rather than clear cookies and sign into EVERY site again (I go on like 20-30 sites, what a nightmare).
Use the search function when you’re in the cookie list and type in, “wordpress_bb”
You will see a list of them. Notice below the list there is info for each cookie. See where it says path? The cookie you need to remove will say ‘bb-admin’ somewhere in the path. Remove it. Click the admin link and you should be good to go.
I logged out and logged in and looked at a few pages and can still access admin. Havent closed the browser yet so we’ll see if this holds.